Document 2k3LrwaxYKKZ7JpVa0dJYdXN

FILE NAME Allied Signal Bendix ASB DATE 1979 June DOC ASB207 DOCUMENT DESCRIPTION Journal Article - Automotive Engineering rth di 7 lereva + pos ST rane.s a . ne ee >. coe ae 20 pre emt gh a . ae sce ay g 7 cm ms . a oS ay x ( my Euture TurbochargersTurbochargers hee dl, { : tet a ( Aer i. | namicsnamics namicsnamics Airbag Designers can affect frictional coefficients of brake ana clutch linings by blending ingredients in their binders Friction modifiers tailor brake a New requirements for friction characteristics In Europe MoS changes in speed load and time lining materials exist because molybdenum disulfide has been At higher speeds and lower loads of the elimination of asbestos in utilized a friction modifier no difference in wear was appar- brake and clutch compositions and the use of small pads for down sized and compact cars Semi- for harder brake pad compositions Comparisons were made between MoS2 and a composition termed ent between MoS and Friction Modifier A but wear was significantly lower than the base re- metallic compositions generally by Dow Corning Friction Modi- sin need some friction modifiers to reduce squeal and wear and pro- duce friction characteristics that fier A Phenolic resin compositions Compositions Three different brake composi- are less temperature Phenolic resins are the most tions were categorized as follows Research on solid friction control common organic binders used in Class High in asbestos and additivies at Dow Corning has pro- friction composites Compositions organic components duced new technology by which of phenolics with high loading Class Less asbestos and or- friction and wear properties can of MoS powder and Friction ganic components plus some inor- be tailored to specific require Modifier A were tested using ganic components ments an Alpha LFW friction and wear Class metallic non- Friction madiffers testing machine Phenolic resin by itself does asbestos composite Class C prototype Friction modifier additives are synergistic blends of tempera- not have the best lubricating properties Addition of MoS2 or lic nonasbestos composite with 10 Friction Modifier A stable materials which can Friction Modififer A provided Table 1 lists the different char- be incorporated into various compositions to provide specific fric- a reduction in wear and friction Generally the phenolic resin with acteristics of the three classes The brake compositions were test- tion wear and carrying pro- Friction Modifier A gave lower ed on the LFW test machine perties Concentrations of one to initial coefficients of friction The results of the testing are six weight percent can reduce and wear values as compared to an listed in Table 2. Good corre- noise levels and dependence of fric- equivalent weight concentration of lation between the LFW tests tion on speed and temperature MoS2 Coefficient of friction for and the general characteristics Additives such as cashew resin the Friction Modifier A formu- provided for each of the classes or graphite have been used for lation changed less with time than was obtained Complete correla- ' many years to control friction the base resin or MoS composi- tion existed for the wear of the properties in brake and clutch tion brake composite and the metal meee compositions Friction composites Additional tests at a lower load mate and very close correlation are composed of a balanced mix- of 13.6 kg and higher speeds re- existed with noise and friction ture of resin plus additives and vealed that formulations with Fric properties at low and high tem- generally contain over a dozen tion Modifier A gave a more con- peratures . ingredients to achieve desired stant coefficient of friction with Class C which produced the 74 sent cnn  3 ry and clutch characteristics Y ^' ' { / 4 / a ^' ~ Characteristic Fade Wear Friction Cold Hot Noise Compressibility Metal Mate Duty For Use Table 1 - General Properties of Brake Linings High Organic Class A Poor Excellent Highest Lowest None Lots No scoring Standard Medium Organic Class B Good Good Lower Higher Little . . Some ~ -.. Some scoring ey Medium heavy NY o \ Low Organic No Asbestos Class C Excellent Fair High + Stab High + Stab Lots Little Lots of scoring Heavy Characteristic Table 1 a 2 - LFW Results at 27.3 kg Load al Variable Speeds Step Change * 1 ' ^ : : Class C + 10 . Class Class B Class C Friction Modi- Wear General Rating LFW on blocks mg | Friction General Rating LFW MT C ~ at 2000 rpm Hot General Rating LFW T C @ 1200 rpm @ 1000 rpm Noise General Rating LFW Metal Mate General Rating LFW Test rinmgg loss Excellent 189 Highest 0.38 49 . Lowest 0.30 107 0.33 115 Nane Very slight at one speed No scoring 13 Good 351 Lower 0.22 38 . Higher 0.28 82 0.38 232 Little None Some scoring 238 Fair 587 High and Stable 0.46-0.39 55 High and Stable , 0.38 143 _ Lots Some at sev speeds Medium scoring 634 _ 490 _ 0.27-0.30 55 0.35 150 None 270 lens 2 |. e oe eo ere e ~ aeee gee Sen are rye one Oe Oe A 2% wen ak . for longer engine life ISSPRO quality instruments Test Lose 27.3 kg - comm Clase C 6 Class C 10 Friction M IA L 4 ie \ R604 PYROMETER The standard of the pyrometer industry is this 3 instrument which features the readout on a 0"10 1800 scale and a 0 to 1000 Scale Contrasting colors on the dist allow easy readabliity and the scale is large for accurate interpretation A609 TURBOCATOR To assist the truck operator in achieving greater fuel and longer engine life this dual scale instrument indicates exhaust temperature on one scals and turbocharger boost pressure on the other By monitoring both scales daily an early indication of engine problems can be foressen INTERMITTENT WINDSHIELD WIPER CONTROL for air powered wipers INSTRUMENT SALES AND INC SERVICE r ere Fig LFW Coefficient of friction vs. speed most noise also gave the most stable frictional properties with speed and temperature as shown in Fig 1. More consistent coefficient of friction properties were obtained from the Class C proto- type between 600 and 1200 rpm Class C prototype produced less noise than the standard Class C brake tween pad The difference be- the maximum and mini- mum coefficient of friction was less with the prototype containing Friction Modifier A than standard Class C material Desirable characteristics of Class B lower wear less noise and a more constant coefficient of friction may be achieved through use of the 10 Friction Modifier A composition It must be noted that this percentage should not be considered as the amount necessary for other compositions compositions Commercial applications New technology for these new friction modifiers was first de- veloped in Dow Corning's Munich Research and Development Lab- oratory The first commercial evaluation and successes were in Eur- opean brake pads Friction Modifier A has been used in the brake pads of a large European car for several years The performance of the brake pad with the new friction modifier was compared with another composition containing MoS2 Comparisons made on a dy namometer showed the following advantages over the MoS2 com- position lower noise level less dependence of friction coef- ficient on temperature decreased wear of the brake pad 30 increase in lifetime decreased wear of the metal disc Since the initial usage in Eur- ope other European brake and clutch material manufacturers have evaluated these new friction modifiers They have generally found them equal or superior to MoS but they do not always provide the same characteristics since different materials are used in each formulation In the U.S.A. a number of brake and clutch friction ma- terial manufacturers have already evaluated the friction modifiers Some have found that in semi- metallic brake pads without asbestos these new additives can reduce noise wear and fade In some cases no improvement was found a Based on SAE paper 790717 Controlled Friction Additives for Brake Pads and Clutches by Harry M. Schiefer and George V. Kubczak Dow Corning Corp. Alun_ adva tech parts pow reas alum 1.1 Alur sure ^ E ^ E ^ E ^ E N~ E ^ N~ E ^ N~ E ^ N~ E ^ N~ E ^ ^^^^^^ ^^^^^^ ^^^^^^ ^^^^^^ ^^^^^^